Rotary fan



C. C. BLACKMORE.

ROTARY FAN.-

APPLICATION FILED MAR. 12, I920.

Patented Mar. 1, 1921.

I ATTORNEY CHARLES C. BLACKMORE, OF DAYTON, OHIO.

ROTARY FAN.

Specification of Letters Patent.

Patented Mar. 1 1921.

Application filed March '12, 1920. Serial No. 365,240.-

T 0 all whom it may concern:

Be it known that I, CHARLES C. BLACK- uonn, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of ()hio, have invented certain new and useful Improvements in Itotary Fans, of'which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to rotary fans and is designed more particularly for use in connection with the cooling systems of internal combustion engines.

The object of the invention is to provide a fan of this kind which will be simple in construction, of a strong, durable character, and which will have a high degree of efiiciency.

It is also an object of the invention to provide such a fan comprising two series of blades and which, with the exception of a hub, maybe made from a single piece of sheet metal. 1

It is also an object of the invention to provide a blank from which the fan may be quickly and easily formed.

Other objects of the invention will appear as the device is described in detail.

In the accompanying drawings Figure 1 is a perspective view of a fan embodying my invention; Fig. 2 is an edge view, par-.

tially broken away, to show the hub construction; Fig. 3 is a plan view of the blank from which the fan of Figs. 1 and 2 is formed; Fig. 4c is a perspective view of a fan showing a slightly different arrangement of the blades; and Fig. 5 is a transverse sectional view taken through the blades.

In these drawings I have illustrated one embodiment of my invention, with a slight modification thereof, and have shown the same as comprising two series of blades 1 and 2, the two series of blades being spaced axially one from the other. The blades of both series are connected at their outer ends with an annular band 3 which forms a rim for the fan and serves not only to connect and brace the fan blades but also constitutes a guard for the fan. The blades are rigidly secured at their outer ends of this rim and are preferably formed integral therewith. To this end I prefer in constructing the fan to provide a blank, as shown in Fig. 3, which consists of an elongated strip of sheet metal which may be bent into circular shape to form the rim of the fan; as shown at 3.

Extending laterally from each edge of the strip 3 is a series of blades, 1' and2, which are adapted to be bent at their points of connection with the rim into positions'at substantially right angles to the rim so that when the rim has been bent into circular form the blades of each series will converge toward the center of the fan. The'blades are bent about their longitudinal axes to give them the desired configuration and in the present construction I haveshown each blade as having one edge bent transversely at a point adjacent to the edge of the rim so that this edge of the blade will lie within the same. The opposite edge of the blade is bent away from the rim and, as here shown, it is provided with an incision, or slit, 5 at a point adjacent to the edge of the rim so that this edge of the fan may be spaced from the edge of the rim. This formation is preferably imparted to the blades before the blank is bent into circular form, but ohviously the order in which the various steps necessary to the formation of the fan are carried out may vary to suit varying conditions. When the rim has been bent into circular form the ends thereof are rigidly c0nnected one to the other by any suitable means as by spotwelding or by rivets. i

, The inner ends of the blades are connectedwith a hub which may be of any suitable character which will support the blades and permit rotary movement to be imparted to the fan as a whole. The hub is here shown at 6 and is preferably provided with an annular portion 7 which projects between the inner ends of the blades ofthe two series and to which these blades are rigidly secured; This annular portion of the hub may be of any desired width and need not necessarily be continuous, but in the present other. As shown in Figs. 1 to 3, the corresponding blades of the two series are arranged in axial alinement and to this end they project directly opposite one another in the blank of Fig. 3. In Fig. 4 I have shown the blades of one series asalternating with a series of short blades arranged between the successive main blades and adapted to in crease the action of the fan on the air. These blades may be provided in any suitable manner but I prefer that they should be struck from the rim 3 at points between the points of connection of the main blades therewith, as shown at 9. As here shown, the blades are tapered in form and are partially severed from the rim at each end of the base line thereof so that they may be turned at the proper angle to the rim.

The construction herein described produces a fan which is of light weight, very simple in its construction and which can be produced at a low cost. Further, the "fan has a high degree of efliciency and theouter ends of the blades are braced and held against displacement relatively one to the other by the rim 3, which also constitutes a guard to prevent the hand of a person working about the fan from coming in contact with the ends-ofthe blades.

'While I have shown and described One embodiment of my invention, together with a slight modification, I wish it to be under stood that'I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention what I claim as new and desire to secure by Letters Patent is: V

' 1. A sheet metal fan, comprising a rim and two series ofblades formed from. a single blank, the blades of one series being spaced axially from the blades of the other series, and a hub with which the inner ends of said blades are connected.

2. A rotary fan comprising a rim, two series of blades formed integral with said rim and extending inwardly from the respective edges thereof, and a hub with which the inner ends of said blades are connected.

3. A rotary fan comprising a rim, two series of blades formed integral with'said rim and extending inwardly from the respective edges thereof, the blades of one series being arranged alternately with the blades of the other series, and a hub with which the inner ends of said blades are connected.

4. Arotary fan comprising a rim, two

series of blades formed integral with said rim and extending inwardly from the re-- spective edges thereof, each of said blades having one edge bent transversely to position it within the adjacent edge of said rim, and having its other edge slit and bent away from said rim, and a hub-with which the inner ends of said blades are connected.

5. A rotary fan comprising a rim, two series of blades formed integral with said rim and extending inwardly from the respective edges thereof, and a hub having an annular portion of a width substantially equal to the width of said rim and to which the inner ends of said blades are secured.

6. A blank for forming a rotary fan comprising a narrow strip of metal adapted to bebent into circular form, and a series of blades extending laterally therefrom and adapted to be bent to positions at'substantially right angles to said strip.

7. A blank for forming a rotary fan com prising a narrow strip of metal adapted to be bent into circular form, and a series of blades extending laterally from each side thereof'and adapted to be bent into positions at substantially right angles to said strip.

.8. A rotary fan comprising a strip of metal bent'into circular form and having its ends rigidly connected one to the other, two

series of blades formed integral with the respective edges of said rim and bent inwardly so that the blades of each series will conver e toward the center of said fan, and a hub with which the inner ends of said blades are connected. V

9. A sheet metal fan, comprising a rim and two series of blades formed from a single blank, the blades of one series being spaced axially from the blades of the other series, a series of supplemental blades also formed from said blank, and a hub with which the inner ends of said blades are connected.

10'. A rotary fan comprising two series of blades, the blades of one series being spaced axially from the blades of the other series, a rim secured to the outer ends of the blades of both series, and a hub with which the inner ends of the blades of both series are connected, said rim having portions struck inwardly therefrom'to form supplemental blades.

In testimony whereof I affix my signature 

